jp7b11509_si_001.zip (25.67 kB)
First-Principles Calculations of Sarin Adsorption on Anatase Surfaces
dataset
posted on 2018-01-09, 00:00 authored by Nam Q. Le, Chinedu E. Ekuma, Brett I. Dunlap, Daniel GunlyckeWe
report density functional theory calculations investigating
the adsorption of the organophosphate nerve agent sarin (GB) on clean
(101), (001)-(1 × 4), and (001)-(1 × 1) surfaces of anatase
titanium dioxide (TiO2). Our calculations show that GB
chemisorbs on all three surfaces by the formation of a dative bond
between the phosphoryl oxygen and a five-coordinated titanium atom
in the surface. The adsorption of GB on the (001)-(1 × 4) and
(001)-(1 × 1) surfaces (−45.1 and −34.8 kcal mol–1) is substantially stronger than on the (101) surface
(−18.2 kcal mol–1). This could be a result
of reactive surface states observed within the TiO2 band
gap at the (001) surfaces but not the (101) surface. Our calculations
show that the GB adsorption passivates these surface states. GB adsorption
also breaks a bridging oxygen bond on both (001) surfaces, leading
to a titanyl group that is also predicted to occur in adsorption of
the simulant dimethyl methylphosphonate (DMMP) on anatase (001). The
ordering of the three anatase surfaces by strength of GB adsorption
is the same as that predicted for DMMP, while the GB adsorption is
predicted to be weaker than DMMP adsorption by 8 kcal mol–1 on the (001)-(1 × 4) surface and by 3 kcal mol–1 on the (101) and (001)-(1 × 1) surfaces.